Delayed-Phase Thrombocytopenia in Patients of Coronavirus Disease 2019 (COVID-19)

Hao Zhou; Wanxin Chen; Ziping Li; Bohan Yang; Qiong Zhou; Ping Wang; Jianhua Zhu; Xuexing Chen; Peng Yang

We began our study based on clinical observation that occasionally several patients developed rapid platelet count decrease after more than 2 weeks of treatment, without evidence of other coagulation abnormalities. Rare cases even suffered severe delayed-phase thrombocytopenia (platelet < 10 × 10 9 /L). Considering natural course of viral infection and treatment outcome of patients, 3 weeks after symptoms onset, most of COVID-19 patients were in the recovery stage [11] . The paradox of delayed-phase thrombocytopenia prompted us to investigate its prevalence and characteristics. With expanded hospitalization capacity and prolonged isolation period, patients can be admitted timely and laboratory results were well followed-up. These enabled us to conduct a longitudinal study on dynamic changes of platelet count.